//2009/08/19 15:21:38
#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <queue>
#include <sstream>
#include <algorithm>

using namespace std;

class Aquarium
{
public:
    int peaceful(int minSize, int maxSize, vector <int> fishSizes)
    {
        int ret = 0;
        for (int i=minSize; i<=maxSize; i++)
        {
            bool flag = true;
            for (int j=0; j<fishSizes.size(); j++)
            {
                if ((fishSizes[j] <= 10*i && fishSizes[j] >= 2*i) || (i <= 10*fishSizes[j] && i >= 2*fishSizes[j]))
                {
                    flag = false;
                    break;
                }
            }
            if (flag) ret++;
        }
        return ret;
    }
};
